Acropora

Acropora
Acropora pulchra
Scientific classification
Kingdom:	Animalia
Phylum:	Cnidaria
Class:	Anthozoa
Order:	Scleractinia
Family:	Acroporidae
Genus:	Acropora Oken, 1815[1]
Species
See text

Acropora is a genus of small polyp stony coral in the phylum Cnidaria.^[2] Some of its species are known as table coral, elkhorn coral, and staghorn coral. Over 149 species are described.^[3] Acropora species are one of the major reef corals responsible for building the immense calcium carbonate substructure that supports the thin living skin of a reef.

Anatomy and distribution

Depending on the species and location, Acropora species may grow as plates or slender or broad branches. Like other corals, Acropora corals are colonies of individual polyps, which are about 2 mm across and share tissue and a nerve net. The polyps can withdraw back into the coral in response to movement or disturbance by potential predators, but when undisturbed, they protrude slightly. The polyps typically extend further at night to help capture plankton and organic matter from the water.

Acropora is most common in shallow reef environments with bright light and moderate to high water motion. Many small reef fishes live near their colonies and retreat into the thicket of branches if threatened.

Threats

Symbiodinium, symbiotic algae, live in the corals' cells and produce energy for the animals through photosynthesis. Environmental destruction has led to a dwindling of populations of Acropora, along with other coral species. Acropora is especially susceptible to bleaching when stressed. Bleaching is due to the loss of the coral's zooxanthellae, which are a golden-brown color. Bleached corals are stark white and may die if new Symbiodinium cells cannot be assimilated. Common causes of bleaching and coral death include pollution, abnormally warm water temperatures, increased ocean acidification, sedimentation, and eutrophication.

Reef-keeping

Close-up of a network of Acropora polyps

Most Acropora species are brown or green, but a few are brightly colored, and those rare corals are prized by aquarists. Captive propagation of Acropora is widespread in the reef-keeping community. Given the right conditions, many Acropora species grow quickly, and individual colonies can exceed a meter across in the wild. In a well-maintained reef aquarium, finger-sized fragments can grow into medicine ball-sized colonies in one to two years. Captive specimens are steadily undergoing changes due to selection which enable them to thrive in the home aquarium. In some cases, fragments of captive specimens are used to repopulate barren reefs in the wild.^[4]

Acropora species are challenging to keep in a home aquarium. They require bright light, stable temperatures, regular addition of calcium and alkalinity supplements, and clean, turbulent water.

Common parasites of colonies in reef aquariums are the Acropora-eating flatworm, and "red bugs" (Tegastes acroporanus).

Species

Acropora (Acroporidae) at French Frigate Shoals, northwestern Hawaiian Islands

References

Further reading

• Reyes-Bermudez A. et al. 2009. Differential expression of three galaxin-related genes during settlement and metamorphosis in the scleractinian coral Acropora millepora. BMC Evolutionary Biology 2009, 9:178. doi:10.1186/1471-2148-9-178

• Shinzato, C., Shoguchi, E., Kawashima, T., Hamada, M., Hisata, K., Tanaka, M., Fujie, M., et al. 2011. Using the Acropora digitifera genome to understand coral responses to environmental change. Nature, advance online publication. doi:10.1038/nature10249

External links

Wikispecies has information related to: Acropora

Wikimedia Commons has media related to Acropora.

• "Acropora". Integrated Taxonomic Information System. 

Corals and coral reefs Stony corals Scleractinia Blue coral Brain coral Elkhorn coral Hermatypic coral Chalice coral Pillar coral Staghorn coral Table coral Soft corals Alcyonacea Black coral Bamboo coral Organ pipe coral Sea fans Sea pens Coral reefs Atoll reef Cay Fringing reef Microatoll Coral reef fish Census of Coral Reefs The Structure and Distribution of Coral Reefs Catlin Seaview Survey Coral regions Deep-water coral African coral reefs Andros, Bahamas Belize Barrier Reef Coral Sea Islands Coral Triangle Florida Keys National Marine Sanctuary Great Barrier Reef Maldives Mesoamerican Barrier Reef System New Caledonia Barrier Reef Pulley Ridge Raja Ampat Islands Red Sea Southeast Asian coral reefs Coral diseases Coral bleaching Black band disease Skeletal eroding band White band disease White pox disease Protection Coral Reef Alliance Coral reef protection Green Fins International Society for Reef Studies Project AWARE Reef Check Reef Ball Other Artificial reef Coral aquaculture Coral dermatitis Coral (precious) Coral rag Coral reef organizations Coral sand Coralline algae Human impact Fire coral Reef resilience Rugosa (extinct) Symbiodinium Tabulate (extinct)